face="Times New Roman Star"EDT 356, VEWT 84, TMN 2, 333, Ё—“я 2, 219-221, Ћексика 160, Stachowski 63. The hypothesis of the word being borrowed from an East Iranian source runs into difficulties, basically because of the lack of early attested forms with -k (only in Tuva dialects and the hypothetical Bulgar source of Russ. бирюк (cf. јникин 128-129)). See also јб. 1, 263 (isn't the East Iranian form itself < Turkic?)